Novelo Galicia Eric, Luis Martínez Moisés Armando, Cordero Carlos
Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
Museo de Zoología "Alfonso L Herrera", Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
PeerJ. 2019 Jun 25;7:e7143. doi: 10.7717/peerj.7143. eCollection 2019.
In many butterfly species, the posterior end of the hindwings of individuals perching with their wings closed resembles a butterfly head. This "false head" pattern is considered an adaptation to deflect predator attacks to less vulnerable parts of the body. The presence of symmetrical damage in left and right wings is considered evidence of failed predator attacks to perching butterflies. In this research, we tested the prediction derived from the deflection hypothesis that the degree of resemblance of the false head area (FH) to a real head, as measured by the number of FH "components" (eyespots, "false antennae", modified outline of the FH area and lines converging on the FH area) present in the hindwings, is positively correlated to the frequency of symmetrical damage in the FH area. We studied specimens from two scientific collections of butterflies of the subfamily Theclinae (Lycaenidae) belonging to the Universidad Nacional Autónoma de México (Colección Nacional de Insectos [CNIN] and Museo de Zoología, Facultad de Ciencias [MZFC]). We scored the presence of symmetrical damage in a sample of 20,709 specimens (CNIN: 3,722; MZFC: 16,987) from 126 species (CNIN: 78 species; MZFC: 117 species; 71 species shared by both collections) whose hindwings vary in the number of FH components, and found that, as predicted, the proportion of specimens with symmetrical damage increases as the number of FH components increases. We also tested the hypothesis that behavioural differences between the sexes makes males more prone to receive predator attacks and, thus, we predicted a higher frequency of symmetrical damage in the FH of males than in that of females. We found that the frequency of symmetrical damage was not significantly different between males and females, suggesting that behavioural differences between the sexes produce no differences in the risk of being attacked. Overall, our results provide support to the idea that the FH of butterflies is an adaptation that deflects predator attacks to less vulnerable parts of the body in both sexes.
在许多蝴蝶物种中，翅膀闭合栖息的个体后翅后端类似蝴蝶头部。这种“假头”图案被认为是一种适应性特征，可将捕食者的攻击引向身体较不易受伤害的部位。左右翅膀出现对称损伤被视为捕食者对栖息蝴蝶攻击失败的证据。在本研究中，我们检验了从偏转假说得出的预测，即通过后翅中存在的“假头”区域（FH）“成分”（眼斑、“假触角”、FH区域的修改轮廓以及汇聚于FH区域的线条）数量来衡量，假头区域与真实头部的相似程度与FH区域对称损伤的频率呈正相关。我们研究了来自墨西哥国立自治大学的两个科学蝴蝶收藏（国家昆虫收藏馆[CNIN]和科学学院动物学博物馆[MZFC]）中Theclinae亚科（灰蝶科）的标本。我们对来自126个物种（CNIN：78种；MZFC：117种；两个收藏共有的71种）的20709个标本（CNIN：3722个；MZFC：16987个）样本中的对称损伤情况进行了评分，这些物种的后翅中FH成分数量各不相同，结果发现，正如预测的那样，随着FH成分数量的增加，出现对称损伤的标本比例也增加。我们还检验了另一个假说，即两性之间的行为差异使雄性更容易受到捕食者攻击，因此，我们预测雄性FH区域对称损伤的频率高于雌性。我们发现，雄性和雌性之间对称损伤的频率没有显著差异，这表明两性之间的行为差异在遭受攻击的风险方面没有差异。总体而言，我们的结果支持了这样一种观点，即蝴蝶的FH是一种适应性特征，可将捕食者的攻击引向两性身体较不易受伤害的部位。
